The present invention relates to a steering knuckle and, more particularly, to a king pin seal assembly therefor.
Heavy-duty vehicles commonly include multiple drive axle assemblies and non-drive steering axles. A wheel end assembly is supported on a steering knuckle, which is supported on an axle assembly. The steering knuckle pivots upon a king pin to provide steering. Conventional king pin arrangements usually include a combination of bushings and thrust bearings.
King pin bearings and bushings are high wear components that typically require replacement every few hundred thousand miles. Frequent maintenance such as re-greasing to flush out wear particles and contamination may also be regularly required. Typically, one or more seals are located about the king pin to minimize contamination of the king pin bearings.
Over time, conventional king pin arrangements may develop some level of end play which may detrimentally affect king pin seals resulting in increased wear and further exacerbation of end play. Due to this wear, conventional king pin seals may provide reduced seal contact. This may be at least partially alleviated by more frequent lubrications to purge contamination and maintain a barrier against moisture and solid contamination. However, if such increased maintenance is not continually performed, the grease barrier may degrade and damage the bushings/bearings.
This situation may be further complicated when the king pin arrangements utilize taper roller bearings on a lower portion of the king pin. Seals on the lower end of king pin tend to accumulate water and contamination on top of the seal lips, which may cause accelerated wear and allow contamination infiltration of the bearing cavity.
Accordingly, it is desirable to provide an effective king pin seal assembly which provides long life with minimal maintenance.